Heat exchanger



Jan. 3, i939. 1 E ANDERSON ET Al. n '2,142,626

HEAT EXCHANGER Filed Feb. 21, 1956 2 Sheets-Sheet l 5 r*4 '194% l I 6 E @A @l a@ i @j o u a .1 a n a o 5 INVENTOR ATTORNEY -Jam. 3, 1939. E. AANDERSON ET AL 2,142,626

HEAT EXCHANGE R Filed Feb. 2l, 1936 4 3 INVENTOR z f a l' 1 5| IIN Patented Jan. 3, 1939 UNITED STATES HEAT EXCHANGER Launcelot E. Anderson, Queens County, Long Island, and Rudolf Kuhlmann, New York, N. Y

Application February 21, 1936, serial No. 65,033y

1s claims..z (o1. 12a-225) The invention herein disclosed relates to a heat exchanger and in one form it is particularly suitable for a boiler for use in conjunction with al heating system, but it is not limited to such use as certain'features thereof are suitable for various types of heat exchangers.

It is an object of this invention to provide a heat exchanger in which there is Aprovided a high ratio of heat transfer surface to the space occupied by the heat exchanger, in which the heat transfer sur aces are accessible for cleaning and in which theprarious parts are easily fabricated and compara .ely inexpensive to manufacture.

Inv accordance with the invention, the heat exchanger is made of boiler plate and consists of sections each of which includes a pair of spaced side walls of irregular configuration. The conguration of the walls is such that they form a series of parallel, communicating compartments.

In each compartment, there is a tube extending longitudinally of the compartment and through the end wall thereof. The compartments contain one fluid and the `other fluid is brought in contact with the outside of the walls of the comv2li partment and the inner surface of the tube.

A feature ofthe invention is'the construction of the tubes which contain a longitudinal, ex,- tended surface extending diagonally of the tube and -which provides additional heat transfer surface.

A boiler embodying the features of this invention is illustrated in the accompanying drawings in which:

Fig. 1 is a side elevation of a sectional boiler constructed in accordance with this invention;

Fig. 2 is a rear elevation of the same;

Fig. 3 is a longitudinal section of one of the sections of the boiler taken along the line 3 3 of Fig. 1;

Fig. 4 is a longitudinal section of the boiler,

part of which is taken along the line A of Fig. 2, and the other part of which is taken along the line laf-4a of Fig. 2;

Fig. 5 is a sectional elevation taken along the 4.5 line 5--5 of Fig. 4; and v Fig. 6 is an enlarged detail illustrating the details `of certain features of the boiler.

. The boiler shown in the drawings is made up of three independent sectionsL'Z, and 3. These 50 sections are mounted upon a base 4 which serves as the ash-pit. The boiler illustrated has a grate 5 for burning coal but the boiler construction isv suitable for the burning of any'other type of fuel. Each boiler of this type has end sections such as the sections I and 3, and one or more intermediate sections such as the section 2. All the intermediate sections are identical and in the essential features of construction the vend-sections are the same as the intermediate sections. The end sections merely differ, as will hereinafter appear, by the provision of an end water wall.

Each section, for example, the central section 2, includes a water dome 6 and a combustion chamber l. The combustion chamber is made up of water legs 8 and 9 at each side of the section and a crown sheet l 0. The outer wall of the water leg is also made of boiler plate and as clearly seen in Fig. 3 it is carried around to form a short horizontal water-leg section, the -crown sheet `forming the inner wall of this horizontal section.

This combustion chamber may rest upon a base such as the base 4 or any other suitable base for use in conjunction with any other type of fuel such as oil. The combustion chamber and the water dome are connected by a series of vertical water legs, two in number. Each water leg is formed by a pair of spaced partitions II-I2 and I3-I4 which extend between the combustion chamber and the water dome. These plates extend longitudinally of the water dome and are spaced transversely thereof but they are of lessI length than the water dome so that the water dome extends over the ends of the plates and terminatesJ in alignment with the outer walls of the water legs 8 and 9. The partitions I3 and Il, making up one water leg, are bent longitudinally of the plate so that they appear of zig-zag shape in end elevation and form a series of verticallyv spaced parallel water chambers Illa, I5 and I6. These water compartments are substantially square in cross section and each water compartment communicates with the water. compartments on either sidethereof. In the particular illustration shown the water compartment I5 communicates both with the Water compartment Ma and the water compartment4 I6. The upper ends of the plates are received in a slot in the water dome and are welded to the water dome so that the upper compartment is in communication with the water dome. At the lower end, `the plates forma water compartment I'I that extends transversely of the combustion chamber.

The ends of the water leg areclosed by plates I8 and I9. 'I'hese plates are cut so that they nt the configuration of the water leg and are received between the plates I3 and Il to which they are welded; they are,also welded to the water dome and the water compartment over the co'mbustion chamber tou form closed water legs. The plates II and I2 are shaped similar to the plates I3 and Il and form a similar water leg having a series of communicating compartments I4a, I5' and I6 therein. The water compartments are so arranged that a diagonal thereof is substantially horizontal and the Water legs are arranged so that the apex of the sides of the Water compartments at the greatest width thereof of one water leg is adjacent the constrictions in the other Water leg so that the adjacentplates of two water legs nest. Plates 20 and 2| close the ends of the Water leg formed by the plates and I2. The adjacent plates |2 and I3 of the water legs are as shown spaced apart and form an irregular gas passage therebetween extending from the combustion chamber to the Water dome.

The plates closing the ends of the water legs have substantially square openings in the center of the sections which close the end of the water` compartments. These openings are provided to receive `iire tubes 22 which extend through the compartments longitudinally thereof. The plates I8 and I9, and 20 and 2|, thus form tube sheets as well as end walls. The tubes received in. these end plates and extending through the compartments are shown enlarged in Fig. 6. Each of these tubes is formed from a single piece of boiler plate material which is bent to form a tube that is square in end elevation. The sheet material is of such a width as to form the necessary side walls of the tube and in addition aV longitudinal extended surface 22a that extends transversely or diagonally of the tube. The whole tube is thus fabricated by bending and only one weld is necessary, that is, a weld joining the side 22b to the extension 22a, the extension 22a constituting a continuation of the side wall 22c.

The ends of the gas passage formed between the plates I2 and |3 are closed by plates 23 and 24. The plate 23 extends from the combustion chamber to the water dome completely sealing the end of the gas passage. 'I'he plate 24, however, does not extend up to the dome, as clearly seen at the left of Fig. 4. With this arrangement, the hot gases from the combustion chamber ow up through the irregular gas passages between successive water legs. Upon reaching the wall of the water dome the gases pass longitudinally of the Water dome and over the edge oi the plate 24 and down through the tubes as indicated by the directional arrows on the draw ings. Similar plates 23a, 24a, and 23h and 2lb close the ends of the gas passages formed between the water leg of the lsection 2 and the adjacent water legs of the sections I and 3.

The ends of the section of the boiler are closed by plates 25 and 26 which with the side walls of the boiler form closed chambers so that as the gas passes along the wall of the water dome and over the plate 2l it is caused to now through the tubes to the other end of the boiler and to the stack which is mounted in the plate 26.

Between each water compartment there is a baule 21. The baille 2I does not extend the full length of the plates but is substantially shorter and is located so that thewater compartments are in communication at each end of the baille. This baille causes the water within the water compartment upon rising to flow longitudinally of the water compartment so that there is a circular circulation of water in the boiler. This circulation is enhanced if the water baiiles of the boiler are slightly inclined to the horizontal. The partitions may be brought together between water compartments leaving a slight space for communication with adjacent water compartments instead of using `the baiiles if desired.

Between the end portions of the Water dome that extend beyond the plates forming the water legs and the water wall of the combustion chamber, there are hollow columns 21a. These co1- umns serve to support the extended end of the water dome and reinforce the combustion chamber, and in addition provide water passages between the water Wall of the combustion chamber and the water dome. For each mid-section of the boiler there are four such columns, one extending from each corner of the combustion chamber to the corresponding corner of the water dome.

An end section for such boilers is the same as the central section above described, with the exception that for the end section I there is provided a water wall 28 extending between the Water dome and the water leg of the combustion chamber, and for the section 2 asimilar water wall 28a. This water leg forms an end wall of the boiler and serves to assist in the circulation of the water. The end Wall is spaced from the partition forming the water compartment adjacent to the wall so that there is a gas passage between the water Wall. and the water leg. The ends of such gas passages are closed by plates such as the plates 29 and 29a in the section I and the plates 29 and 29a in the section 3 which are cut to be received between the water wall and the adjacent partition of the water leg. The plate at one end of the gas passage such as the plate 29 extends to the water dome and completely seals the end of the gas passage; the plateat the other end, such as the plate 29a, does not extend to the water dome to leave a space for the passage of the gas over the edge thereof. It is of courseunderstood that any heat insulating material might be used in place of these end plates for the gas passages. The end water Walls form with the plates 26 and 21 and similar plates on the sections I and 3, gas chambers at the ends of the boiler.

The three sections of the boiler illustrated in the drawings are connected together by a pipe,

line 29h which connects the three water domes together, and another pipe line 30 connects the water legs 'of the three sections together.

Each section of the boiler is provided with a door at one side thereof such as the door 3| hingedly mounted on the plate 25. The door 3| covers an opening in the plate and when open gives free access for cleaning the tubes of the boiler. Similarly, the plates which close the gas passages at this end oi the boiler may be arranged so that these plates may be removed and the gas side of the partitions of the water compartments and the water legs likewise cleaned.

In Fig. 6 there is shown a modiiied form oi the plates that make up thev sides of the water compartments and gas passages. As illustrated in Fig. 6, these partitions may be made up of a series of plates 32 each of a width suiiicient to form one side of a water compartment. When so constructed, the edge of one plate 3l which joins to'the plate 32, protrudes beyond the edge of the plate 32 to form a flange 33a that. constitutes an extended surface extending into the gas passage. This flange may have various shapes so as to etl'ect a slight turbulence of the gas without materially vincreasing the frictional resistance to the passage of the gas because it is located at the point where the gas passage iS the widest and it can be projected in the direction of the gas ow. A more eclent-contact of the gas with the heating surface may thus be obtained.

With a boiler constructed as described, there is a high ratio of heating surface to the cubical content of the heat exchange section of the boiler. It will be foundthat the ratio of the heating surface of a fire tube to the heating surface of the watercompartment surrounding the tube is 0.8 or greater and the ratio of the diagonal or diameter of a fire tube to the largest distance between the water walls enclosing it, is one or greater.

A boiler constructed as illustrated in the drawings has several distinct advantages, among which are the facts that there is obtained a circulation of water without the use of headers; that the entire areas of the gas sideof the heat transfer surfaces are readily accessible for cleaning; that all welds made in the construction of the boiler are short and straight and all welds are accessible; that the entire boiler is formed of small pieces of boiler plate which are easily shaped into the proper configurations bypressing operations; and that the boiler is a sectional boiler so that by keeping end and center sections in stock, boilers of various sizes may be supplied. These features of construction of course render the boiler comparatively inexpensive to m'anufacture.

It will be obvious that various changes may be I made by those skilled in the art in the details of the embodiment of the invention illustrated in the drawings and described in detail above within the principle and scope of the invention as expressed in the appended claims.

We claim:

1. In a boiler, the combinationV comprising a water dome, a combustion chamber, a series of metal-plate partitions extending longitudinally of the water dome and between the water dome and the combustion chamber, the partitions being spaced apart transversely of the water dome and forming. a series of alternate water legs and gas passages and having an irregular contour forming a series of vertically spaced, communicating water compartments in each water leg and an irregular gas passage between adjacent water legs, and a re tube within each water compart- Ament and extending longitudinally thereof.

2. In aboiler, the combination comprising a water dome, a combustion chamber, a serias of metal-plate partitions extending longitudinally of the water dome and between the water dome and the combustion chamber, the partitions being spaced apart transversely of the water dome`and lforming a series of alternate water legs and gas passages and having an irregular contour forming a series of vertically spaced, communicating water compartments in each water leg and an irregular gas passage between adjacent water legs, and a fire tube within each water compartment and extending longitudinally thereof, the fire tube having a longitudinal internal extended surface.

3. In a boiler, the combination comprising a water dome, a combustion chamber, a series of metal-plate partitions extending longitudinally of the water dome and between the water dome and the combustion chamber, the partitions being spaced apart transversely of the water dome and forming a series of alternate, vertical water legs and gas passages, each partition including a series of sections inclined to the vertical and forming a group of vertically spaced, communicating water compartments in each water leg and an irregular gas passage-,between adjacent water legs, and a re tube within each water compartment andextending longitudinally thereof.

4. In a boiler, the combination comprising a water dome, a combustion chamber, a series of metal-plate partitions extending longitudinallyl of the water dome and between the water dome and the combustion chamber, the partitions being spaced apart transversely of the water dome and forming a series of alternate, vertical water legs and gas passages, each partition including a series of sections inclined to the vertical and forming a group of .vertically spaced, communicating water compartments in each water leg and an irregular gas passage between adjacent water legs, and a fire tube of polygonal shape in cross-section within each water compartment and extending longitudinally thereof.

5. In a boiler, the combination comprising a water dome, a combustion chamber, a series of metal-plate partitions extending longitudinally of the water dome and between the water dome and the combustionl chamber, the partitions being spaced apart transversely of the water dome and ing a group of vertically spaced, communicating water compartments in each water leg and an irregular gas passage between adjacent water legs, and a fire tube of polygonal shapein cross-section within each water compartment and extending longitudinally thereof, 'the fire tube having an internal transverse extended surface.

6. In a boiler,y the combination comprising a water ldome, a combustion chamber, a series of metal-plate partitions extending longitudinally of the water dome and between the water dome and the combustion chamber, the partitions being spaced apart transversely of the water dome and forming a series of alternate, vertical water legs and gas passages, each partition including a series of sections inclined to the vertical and forming a group of vertically spaced, communicating water compartments in each water leg and an irregular gas passage between adjacent water legs, and a fire tube substantially square in cross-section within each water compartment and extending longitudinally thereof, the fire tube having an internal longitudinal, diagonal extension.

'7. In a heat transfer device, the combination comprising metal-plate partitions forming a water leg and a gas passage on each side of the water leg, the partitions having an irregular surface to form a series of communicating water compartments in each water leg and an irregular gas passage on each side of the water leg, and -a gas tube extending through each water compartment.

8. In a heat transfer device, the combination comprising metal-plate partitions forming a. water 'leg and a gas passage on each side of the water leg, the partitions having an irregular surface to `form a series of communicating water compartments in each water leg and an irregular gas passage on each' side of the water leg,` and a gas tube extending through each water compartment, and each ltvater compartment having a heating surface of the inner gas tube greater than themheating surface' of the enclosing walls of the water compartment.

9. In a heat transfer device, the combination comprising metal-plate partitions forming a. water leg and a gas passage on each side of the water leg, the partitions having'an irregular surfaceto form a series of communicating water compartments in each water leg and an irregular gas passage on each side of the water leg, a gas tube extending through each water compartment, and a baille between communicating water compartments of lesser length than the water compartment to effect a longitudinal movement of the water in the compartment.

10. In a heat transfer device, the combination comprising metal-plate partitions forming a water leg and a gas passage on each side of the water leg, the partitions having an irregular surface to form a series of communicating water -compartments in each water leg and an irregular gas passage on each side of the water leg, and a gas tube extending through each water compartment and each water compartment having a relation to the gas tube such that the ratio of the largest transverse measurement of the gas tube to the largest width of water space in the water compartment is greater than one.

11. In a boiler, the combination comprising a water dome, -a combustion chamber, and a series of metal-plate partitions extending longitudinally of the water dome and between the water dome and the combustion chamber, the partitions being spaced apart transversely of the water dome and arranged in pairs, each pair of partitions forming a water leg having a series of vertically spaced, communicating water compartments of polygonal shape in cross-section and a series of water passages between successive compartments of lesser width than the water compartments.

12. In a boiler, the combination comprising a water dome, a combustion chamber, and a series of metal-plate partitions extending longitudinally of the water dome and between the water dome and the combustion chamber, the partitions being spaced apart transversely and shaped to form a series of alternate water legs and gas passages, the partitions having an irregular contour whereby a series of vertically spaced water compartments are formed in each water leg communicating through passages between successive compartments of lesser width than the compartments and the said gas passages between successive water legs are rendered irregular.

13. In a heat transfer device, the combination comprising spaced, irregular walls forming a series of parallel, communicating compartments therebetween for one of the uids between which heat is to be transferred, end walls closing the ends of the compartments, the end walls having openings therethrough at each compartment, and a tube extending through each compartment and each tube including a longitudinal extension within the tube extending transversely thereof,

the outer surfaces of the walls of the uid com-I partments and the internal surface of the tubes forming heat exchange surfaces for transferring heat between uid in the compartments to fluid in contact with such. surfaces.

LAUNCELOT E. ANDERSON. RUDOLF 

